It is the handler for the failed complete message. Add a flag to
remember if we received a such message from peer, if so, do not send
back the failed complete message back to the peer when running
close_session with failed status.
When a node shutdown itself, it will send a shutdown status to peer
nodes. When peer nodes receives the shtudown status update, they are
supposed to close all the sessions with that node becasue the node is
shutdown, no need to wait and timeout, then fail the session.
This change can speed up the closing of sessions.
Currently, send_complete_message is not used. We will use it shortly in
case the local session is failed. Send a complete message with failed
flag to notify peer node that the session is failed so that peer can
close the session. This can speed up the closing of failed session.
Also rename it to send_failed_complete_message.
The complete_message is not needed and the handler of this rpc message
does nothing but returns a ready future. The patch to remove it did not
make into the Scylla 1.0 release so it was left there.
Use this flag to notify the peer that the session is failed so that the
peer can close the failed session more quickly.
The flag is used as a rpc::optional so it is compatible use old
version of the verb.
Streaming ususally takes long time to complete. Abort it on false
positive idle detection can be very wasteful.
Increase the abort timeout from 10 minutes to a very large timeout, 300
minutes. The real idle session will be aborted eventually if other
mechanisms, e.g., streaming manager has gossip callback for on_remove
and on_restart event to abort, do not abort the session.
Fixes#2197
Message-Id: <57f81bfebfdc6f42164de5a84733097c001b394e.1494552921.git.asias@scylladb.com>
- introcduced "seastarx.hh" header, which does a "using namespace seastar";
- 'net' namespace conflicts with seastar::net, renamed to 'netw'.
- 'transport' namespace conflicts with seastar::transport, renamed to
cql_transport.
- "logger" global variables now conflict with logger global type, renamed
to xlogger.
- other minor changes
Now that we have the new interface to make readers with ranges, we can
simplify the code a lot.
1) Less readers are needed
before: number of ranges of readers
after: smp::count readers at most
2) No foreign_ptr is needed
There is no need to forward to a shard to make the foreign_ptr for
send_info in the first phase and forward to that shard to execute the
send_info in the second phase.
3) No do_with is needed in send_mutations since si now is a
lw_shared_ptr
4) Fix possible user after free of 'si' in do_send_mutations
We need to take a reference of 'si' when sending the mutation with
send_stream_mutation rpc call, otherwise:
msg1 got exception
si->mutations_done.broken()
si is freed
msg2 got exception
si is used again
The issue is introduced in dc50ce0ce5 (streaming: Make the mutation
readers when streaming starts) which is master only, branch 1.5 is not
affected.
Currenlty we make the mutation readers for streaming at different
time point, i.e.,
do_for_each(_ranges.begin(), _ranges.end(), [] (auto range) {
make a mutation reader for this range
read mutations from the reader and send
})
If there are write workload in the background, we will stream extra
data, since the later the reader is made the more data we need to send.
Fix it by making all the readers before starting to stream.
Fixes#1815
Message-Id: <1479341474-1364-2-git-send-email-asias@scylladb.com>
There are places in which we need to use the column family object many
times, with deferring points in between. Because the column family may
have been destroyed in the deferring point, we need to go and find it
again.
If we use lw_shared_ptr, however, we'll be able to at least guarantee
that the object will be alive. Some users will still need to check, if
they want to guarantee that the column family wasn't removed. But others
that only need to make sure we don't access an invalid object will be
able to avoid the cost of re-finding it just fine.
Signed-off-by: Glauber Costa <glauber@scylladb.com>
Message-Id: <722bf49e158da77ff509372c2034e5707706e5bf.1478111467.git.glauber@scylladb.com>
Wrapping ranges are a pain, so we are moving wrap handling to the edges.
Since cql can't generate wrapping ranges, this means thrift and the ring
maintenance code; also range->ring transformations need to merge the first
and last ranges.
Message-Id: <1478105905-31613-1-git-send-email-avi@scylladb.com>
Remove inclusions from header files (primary offender is fb_utilities.hh)
and introduce new messaging_service_fwd.hh to reduce rebuilds when the
messaging service changes.
Message-Id: <1475584615-22836-1-git-send-email-avi@scylladb.com>
"This series improves repair by
1) using less streaming sessions
2) reducing unnecessary streaming traffic
3) fixing a hang during shutdown
See commit log for "repair: Reduce stream_plan usage", "repair: Reduce
unnecessary streaming traffic" and "streaming: Fail streaming sessions
during shutdown" for details.
Tested with repair_additional_test.py."
Using make_streaming_reader for streaming on the sender side, it has
the following advantages:
- streaming, repair will not pollute the row cache on the sender side
any more. Currently, we are risking evicting all the frequently-queried
partitions from the cache when an operation like repair reads entire
sstables and floods the row cache with swathes of cold data from they
read from disk.
- less data will be sent becasue the reader will only return existing
data before the point of the reader is created, plus bounded amount
of writes which arrive later. This helps reducing the streaming time
in the case new data is being inserted all the time while streaming is
in progress. E.g., adding a new node while there is a lot of cql write
workload.
Fixes#382Fixes#1682
We print the following messages even if there is no stream_session with
that peer. It is a bit confusing.
INFO 2016-09-23 08:26:37,254 [shard 0] stream_session - stream_manager:
Close all stream_session with peer = 127.0.0.1 in on_restart
INFO 2016-09-23 08:26:37,287 [shard 0] stream_session - stream_manager:
Close all stream_session with peer = 127.0.0.3 in on_remove
Print only when the streaming session with the peer exists.
Remove clustering_key_filter_factory and clustering_key_filtering_context.
Use partition_slice directly with a static get_ranges method.
Signed-off-by: Piotr Jastrzebski <piotr@scylladb.com>
From Paweł:
This is another episode in the "convert X to streamed mutations" series.
Hashing mutations (mainly for repair) is converted so that it doesn't
need to rebuild whole mutation.
The first part of the series changes the way streamed mutations deal
with range tombstones. Since it is not necessary to make sure we write
disjoint tombstones to sstables there is no need anymore for streamed
mutations to produce disjoint tombstones and, consequently, no need for
range tombstones to be split into range_tombstone_begin and
range_tombstone_end.
The second part is the actual hashing implementation. However, to ensure
that the hash depends only on the contents of the mutation and no the
way it is stored in different data sources range tombstones have to be
made disjoint before they are hashed.
This series also ensures that any changes caused by streamed mutations
to hashing and streaming do not break repair during upgrade.
The receiving side needs to handle fragmented mutations properly so that
isolation guarantees are not broken. If the receiving node may be an old
one do not fragment mutations.
Signed-off-by: Paweł Dziepak <pdziepak@scylladb.com>
Commit 206955e4 "streaming: Reduce memory usage when sending mutations"
moved streaming mutation limiter from do_send_mutations() to
send_mutations(). The reason for that was that send_mutation() did full
mutation copies. That's no longer the case and streaming limiter should
be moved back to do_send_mutation() in order to provide back pressure to
fragment_and_freeze().
Signed-off-by: Paweł Dziepak <pdziepak@scylladb.com>
If mutations are fragmented during streaming a special care must be
taken so that isolation guarantees are not broken.
Mutations received with flag "fragmented" set are applied to a memtable
that is used only by that particular streaming task and the sstables
created by flushing such memtables are not made visible until the task
is complte. Also, in case the streaming fails all data is dropped.
This means that fragmented mutations cannot benefit from coalescing of
writes from multiple streaming plans, hence separate way of handling
them so that there is no loss of performance for small partitions.
Signed-off-by: Paweł Dziepak <pdziepak@scylladb.com>
plan_id is needed to keep track of the origin of mutations so that if
they are fragmented all fragments are made visible at the same time,
when that particular streaming plan_id completes.
Basically, each streaming plan that sends big (fragmented) mutations is
going to have its own memtables and a list of sstables which will get
flushed and made visible when that plan completes (or dropped if it
fails).
Signed-off-by: Paweł Dziepak <pdziepak@scylladb.com>
dtest takes error level log as serious error. It is not a serious error
for streaming to fail to send a verb and fail a streaming session, for
example, the peer node is gone or stopped. Switch to use log level warn
instead of level error.
Fixes repair_additional_test.py:RepairAdditionalTest.repair_kill_3_test
Fixes: #1335
Message-Id: <0149d30044e6e4d80732f1a20cd20593de489fc8.1465979288.git.asias@scylladb.com>
Limit disk bandwidth to 5MB/s to emulate a slow disk:
echo "8:0 5000000" >
/cgroup/blkio/limit/blkio.throttle.write_bps_device
echo "8:0 5000000" >
/cgroup/blkio/limit/blkio.throttle.read_bps_device
Start scylla node 1 with low memory:
scylla -c 1 -m 128M --auto-bootstrap false
Run c-s:
taskset -c 7 cassandra-stress write duration=5m cl=ONE -schema
'replication(factor=1)' -pop seq=1..100000 -rate threads=20
limit=2000/s -node 127.0.0.1
Start scylla node 2 with low memory:
scylla -c 1 -m 128M --auto-bootstrap true
Without this patch, I saw std::bad_alloc during streaming
ERROR 2016-06-01 14:31:00,196 [shard 0] storage_proxy - exception during
mutation write to 127.0.0.1: std::bad_alloc (std::bad_alloc)
...
ERROR 2016-06-01 14:31:10,172 [shard 0] database - failed to move
memtable to cache: std::bad_alloc (std::bad_alloc)
...
To fix:
1. Apply the streaming mutation limiter before we read the mutation into
memory to avoid wasting memory holding the mutation which we can not
send.
2. Reduce the parallelism of sending streaming mutations. Before we send each
range in parallel, after we send each range one by one.
before: nr_vnode * nr_shard * (send_info + cf.make_reader memory usage)
after: nr_shard * (send_info + cf.make_reader memory usage)
We can at least save memory usage by the factor of nr_vnode, 256 by
default.
In my setup, fix 1) alone is not enough, with both fix 1) and 2), I saw
no std::bad_alloc. Also, I did not see streaming bandwidth dropped due
to 2).
In addition, I tested grow_cluster_test.py:GrowClusterTest.test_grow_3_to_4,
as described:
https://github.com/scylladb/scylla/issues/1270#issuecomment-222585375
With this patch, I saw no std::bad_alloc any more.
Fixes: #1270
Message-Id: <7703cf7a9db40e53a87f0f7b5acbb03fff2daf43.1464785542.git.asias@scylladb.com>
